Korean industrial group Hyosung has accused the country's largest power-transmission components manufacturer, LSIS, of stealing its technology.

According to a report Tuesday by The Korea Times, Hyosung is demanding compensation from LSIS, claiming the latter stole technology related to power transmission and control, costing it "several billions of dollars".

The Seoul Metropolitan Police also are questioning four former Hyosung executives who moved to LSIS on suspicions they leaked trade secrets related to high-voltage, direct-current (HVDC) transmission technology to their new employer.

Hyosung executives told the Korean news site a former Hyosung executive, identified as Lee, had downloaded documents on HVDC technology from the company's servers to his extended hard disk drive without permission and was suspected of providing the files to LSIS.

"This was definitely a crime and that is why police are investigating it," a senior Hyosung executive said. "Our knowledge is that the case has been recently passed to prosecutors."

He said Hyosung's future technology related to HVDC, static synchronous compensator (STATCOM) smart grids, wind power generation, solar cells and electric vehicles was leaked to LSIS and the economic loss could be as much as 800 billion won (US$710 million). LSIS was "definitely behind this as it has been looking for shortcut to [Hyosung's] advances", he added.

LSIS declined to comment when approached by The Korea Times, but is understood to be preparing for an "extensive legal battle".